It is known to create lettering, numbering and simple carvings in stone surfaces, most particularly in burial headstones and monuments, by sandblasting or cutting into a stone surface to form lines and curves of removed material. A sandblasting process is typically carried out with the use of a rubber stencil, limiting the process to relatively thick lines and large letters or numbers.
Some years ago, the use of lasers appeared in the monument industry but was typically limited to performing on dark granites. More recently, U.S. Pat. No. 7,919,191 was issued to George M. Arnold describing a method of creating pigmented images on stone such as granite. The Arnold method includes the steps of masking the stone substrate in an image area burning through the mask to pit the stone substrate, applying pigmented paint over the image area and thereafter removing the remains of the mask. Lithochrome paint is applied as base paint and also pigmented paint. Lithochrome paint is acrylic-based surface bonding paint. During freeze and thaw weathering cycles, it blisters easily and therefore, can separate from the granite surface.